The invention concerns a connecting part for electrical warp stop motions on weaving machines, which serves to conduct electricity to several contact bars, positioned parallel to one another, and each consisting of two conductor bars insulated against each other.
As is known, electrical warp stop motions serve to close an electric current, in the event of a warp thread breaking, and thereby stop the weaving machine. The electric current is closed by means of the drop wires resting on the warp threads. When a warp thread breaks, the drop wire falls on to its corresponding contact bar and thereby electrically connects the two conductor bars of this contact bar. Usually each contact bar consists of an outer, U-shaped conductor bar and an inner, flat conductor bar with an insulation between them, whereby the inner conductor bar has a protruding narrow edge against which the slanted top edge of the contact bar slot of the drop wire hits.
All the inner and outer conductor bars of the contact bars positioned parallel to each other must be connected, in parallel position, to an electrical source. This is done by means of the connecting part. The connecting part should be easily mountable and removable by hand to allow for easy insertion of the contact bars into the warp stop motion when, for instance, a new warp is gated. There are various known executions of connecting parts of which one part, consisting of insulating material, evidences parallel slots to accommodate the contact bars. Either an electrical conductor, stretching across all the slots and touching all the inner conductor bars, is screwed to the part consisting of insulating material and the outer conductor bars resting in the slots of the mentioned part are connected to a further electrical conductor serving both, the disadvantage of which is that every time the contact bars are inserted or removed, all the screws have to be loosened. Or, as in another type of execution, the connecting part, mountable from above on to all the contact bars, has a lengthwise part consisting of insulating material and having slots. This part is foreseen with a slider, moveable in longitudinal direction by means of spring action, and having the same number of downwards reaching fingers with hook shaped ends, as there are slots. The fingers grip around the under edges of all the contact bars when the slotted part, consisting of insulating material, is mounted on the upper edges of all the contact bars. This connecting part is mountable on to all the contact bars in one easy motion of the hand. In the case of every slot there are moveable contact pins against which each inner conductor bar of each contact bar rests and, furthermore, conducting stirrups, that reach to the end of every slot and overlap the U-shaped outer contact bars. The many springy contact pins and conducting stirrups, which are electrically connected to each other by means of the electric conductor reaching across the length of the connecting part and which are connected to contacts in the form of plug pins, as well as the holder with fingers having hook-shaped ends, make this practical and handy connecting part relatively expensive to manufacture.
The object of the present invention, therefore is to eliminate the disadvantage of the relatively involved construction evidenced in the price, as well as the further disadvantage which is that, due to the oscillations and the shaking of the weaving machine in operation, this described known connecting part, consisting of many individual parts, is subject to relatively severe wear and tear. A connecting part, simpler in construction and consisting of fewer parts than the mentioned one, must however, just as the known and above-described connecting part, fulfill the prerequisite that every contact bar is in springy contact with the electrical conductor in the connecting part that connects each to the other. This prerequisite is met in the above described known connecting part by means of the mentioned springy contact pins and is unavoidable due to the manufacturing tolerances of the contact bars that may differ up to 1 mm in upright measurement. A non-springy contact, therefore, would make the functioning of the connecting part questionable, all the more so, in view of the oscillations of the running weaving machine which are transferred to the connecting part.